Abstract

The catalytic conversion of dihydroxyacetone (DHA) to lactic acid (LA) via pyruvaldehyde (PA) in an aqueous medium was studied using different homogeneous metal salts. A kinetic model was developed and the parameters corresponding to each reaction step were estimated. Agreement between experiments and simulated results was excellent and the performance of the different catalysts was consistent with previous studies described in the literature. Aluminium salts, which show the best performance, were tested in a whole range of concentrations and at different pH values in order to identify the catalytically active ionic species. It was confirmed that the DHA to pyruvaldehyde (PA) dehydration step is catalyzed by both Brønsted and Lewis acids, whereas the consecutive reaction of PA to LA is catalyzed solely by Lewis acids. Moreover, a comparison of the thermodynamic analysis of the reaction medium and the kinetic parameters demonstrated that cationic hydroxyl-aluminium complexes [Al(OH)h](3−h)+ formed in situ by the hydrolysis of aluminium aqua complexes like [Al(OH2)6]3+ are the most active Lewis acids.

Authors contributing to RSC publications (journal articles, books or book chapters)
do not need to formally request permission to reproduce material contained in this
article provided that the correct acknowledgement is given with the reproduced material.

Reproduced material should be attributed as follows:

For reproduction of material from NJC:
Reproduced from Ref. XX with permission from the Centre National de la Recherche
Scientifique (CNRS) and The Royal Society of Chemistry.

For reproduction of material from PCCP:
Reproduced from Ref. XX with permission from the PCCP Owner Societies.

For reproduction of material from PPS:
Reproduced from Ref. XX with permission from the European Society for Photobiology,
the European Photochemistry Association, and The Royal Society of Chemistry.

For reproduction of material from all other RSC journals and books:
Reproduced from Ref. XX with permission from The Royal Society of Chemistry.

If the material has been adapted instead of reproduced from the original RSC publication
"Reproduced from" can be substituted with "Adapted from".

In all cases the Ref. XX is the XXth reference in the list of references.

If you are the author of this article you do not need to formally request permission
to reproduce figures, diagrams etc. contained in this article in third party publications
or in a thesis or dissertation provided that the correct acknowledgement is given
with the reproduced material.

Reproduced material should be attributed as follows:

For reproduction of material from NJC:
[Original citation] - Reproduced by permission of The Royal Society of Chemistry (RSC) on behalf of the
Centre National de la Recherche Scientifique (CNRS) and the RSC

For reproduction of material from PCCP:
[Original citation] - Reproduced by permission of the PCCP Owner Societies

For reproduction of material from PPS:
[Original citation] - Reproduced by permission of The Royal Society of Chemistry (RSC) on behalf of the
European Society for Photobiology, the European Photochemistry Association, and
RSC

For reproduction of material from all other RSC journals:
[Original citation] - Reproduced by permission of The Royal Society of Chemistry

If you are the author of this article you still need to obtain permission to reproduce
the whole article in a third party publication with the exception of reproduction
of the whole article in a thesis or dissertation.

Information about reproducing material from RSC articles with different licences
is available on our Permission Requests page.